WFDC2 and ovarian cancer: While serum HE4 as a biomarker for ovarian cancer has been well recognized [18], serum HE4 levels were also found to be higher in cases with PDAC than in the controls with an SN of 45.83% and SP of 93.75% when the cutoff was set at 4.59 ng/mL [19], and the combination of HE4 and CA19-9 increased the SN to 83.33% [19,20].